Increased plant growth from nitrogen addition should conserve phosphorus in terrestrial ecosystems
Increased plant growth from nitrogen addition should conserve phosphorus in terrestrial ecosystems
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DOI：
10.1073/pnas.0711618105
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发表时间：
2008-02-12
影响因子：
11.1
通讯作者：
de Mazancourt, Claire
中科院分区：
文献类型：
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作者：
Perring, Michael P.;Hedin, Lars O.;de Mazancourt, Claire
近年来，向生态系统输入的有效氮（N）有所增加。有有限的一般理解如何增加N输入影响其他潜在限制养分的循环和保留。使用植物-土壤养分模型，并明确耦合N和磷（P）在植物生物量，我们研究增加N供应的生态系统循环和保留的P的影响，假设N的主要影响是增加植物生长。我们发现不同的反应，在P循环取决于特定的途径，营养物质从生态系统中丢失。如果植物有效磷的损失的相对倾向大于不容易获得的有机磷的损失，这是第一个理论证明，生态系统规模的养分循环的耦合响应严重依赖于养分流失的形式，促进P的保留。磷保留可能会减少，或逆转，这取决于动力学和缓冲反应磷池的大小。这些属性决定了反应池的能力，以提供可用的P.参数化的模型在一系列的森林生态系统跨越各种环境和气候条件表明，增强植物生长，由于增加N应触发增加P保护生态系统内，同时导致更多的溶解有机磷的损失。我们讨论了N的影响的大小和方向也可能取决于其他过程。
Inputs of available nitrogen (N) to ecosystems have grown over the recent past. There is limited general understanding of how increased N inputs affect the cycling and retention of other potentially limiting nutrients. Using a plant-soil nutrient model, and by explicitly coupling N and phosphorus (P) in plant biomass, we examine the impact of increasing N supply on the ecosystem cycling and retention of P, assuming that the main impact of N is to increase plant growth. We find divergent responses in the P cycle depending on the specific pathway by which nutrients are lost from the ecosystem. Retention of P is promoted if the relative propensity for loss of plant available P is greater than that for the loss of less readily available organic P. This is the first theoretical demonstration that the coupled response of ecosystem-scale nutrient cycles critically depends on the form of nutrient loss. P retention might be lessened, or reversed, depending on the kinetics and size of a buffering reactive P pool. These properties determine the reactive pool's ability to supply available P. Parameterization of the model across a range of forest ecosystems spanning various environmental and climatic conditions indicates,that enhanced plant growth due to increased N should trigger increased P conservation within ecosystems while leading to more dissolved organic P loss. We discuss how the magnitude and direction of the effect of N may also depend on other processes.